Digging and Cultivating Methods for Thriving Crops
Digging and cultivating
Thorough cultivations and good drainage help to provide the conditions in which crops will thrive. Tackled the right way, the work need not be as heavy as many beginners believe.
Digging is the first stage of preparing soil for cropping. In spite of experiments to find alternatives, it has remained standard practice because it does a number of essential things effectively.
Digging breaks up the top spit (spade-depth) of soil, leaving the surface in a semi-rough condition to be broken down by frost and rain into fine crumbs suitable for sowing and planting. It improves drainage, yet makes it easier for moisture to be drawn upwards to the plants’ roots.
Digging also aerates the soil, providing suitable conditions for the bacteria that make soil nutrients available to plants. It provides an opportunity for working manure into the soil, for burying annual weeds and for removing deep-rooted perennials.
Is digging necessary?
Although practised by some gardeners, methods of cultivation which avoid digging are still not generally accepted by the majority. For the beginner taking over a garden for the first time, they are impracticable; nor, contrary to popular belief, are they especially labour-saving: The essential feature of a ‘no-digging’ routine is that the soil, once cleared of perennial weeds, is kept covered with a layer of matured compost, adding at least 1in (25 mm) a year. The action of bacteria and earthworms mixes this organic material with the soil, so that the upper 4-6in (100-150 mm) becomes rich in humus and very fertile.
The surface remains well broken and easily worked, and the soil texture below is maintained by decaying vegetable matter and the presence of a large earthworm population.
Putting the theory into practice, however, may need more compost than the average garden can produce. In a new garden, where no compost will be available until a year after the first heap is started, it is out of the question.
To illustrate the scale of the problem, it is fair to assume that vegetable matter piled 12in (305 mm) deep will, when rotted down, produce a 2-3in (50-75 mm) layer of compost. Therefore, to estimate the amount of compost material you would have to collect for a full-scale ‘no-dig’ programme you must visualise your kitchen garden covered each year with, say, a 6in (150 mm) layer of greenstuff, leaves, etc. This may be difficult to provide.
A further difficulty about giving up deep cultivation is the probable re-growth of perennial weeds. When left undisturbed they establish themselves and spread rapidly. Farmers who practise direct drilling, which is a ‘no-ploughing’ technique, control weeds by the use of herbicides on a scale that the private gardener would probably be unable or unwilling to imitate.
If you wish to experiment with ‘no-digging’ techniques, you are most likely to succeed on well-drained, weed-free soil. Mark out a small trial plot and treat it in this way for several seasons — assuming that you have compost to spare for the experiment.
This follows a principle that should be applied to most gardening innovations — to try out new methods and new varieties on a small scale, while relying on conventional ways and well-tried varieties until the new ones are shown to be better.
How to dig
If tackled sensibly, digging is neither as difficult nor as strenuous as many believe. Once the knack is acquired, digging a vegetable plot can be a satisfying and even relaxing occupation.
However, beginners should not attempt too much at first, even when the work seems to be going well and easily. An hour at a time is a reasonable limit until the spine and back muscles are attuned to the unaccustomed movements.
How to Handle A Spade
With the shaft vertical, place your left foot on the tread ( if you are right-handed) and push the blade down.
With your left hand near the base of the shaft, tilt the shaft backwards and lift the blade just clear of the soil.
Tilt the blade to the right so that the spit of soil is inverted on the far side of the trench. Keep the trench open.
Types of digging
Normal digging consists of inverting the top spit of soil, and at the same time burying annual weeds, removing the roots of perennial weeds, and incorporating compost or manure if required.
This is known as single digging, and is adequate for most purposes. The alternative, which involves turning the soil two spits deep and is known as double digging, takes longer but in certain conditions gives better results.
Double digging is most worthwhile before growing deep-rooted crops, such as parsnips or runner beans, on land where the subsoil is compacted. But as a rule it is something to try once the basic technique of digging has been mastered.
Whichever method you choose, avoid digging when the soil is soggy or frozen.
Sandy, free-draining soils can be dug without difficulty at almost any time of year, except during a spell of freezing weather in winter, but late autumn is the best time to dig clay soils. They should not then be too wet, and winter frosts will crumble the soil into a fine tilth for sowing seeds in spring.
The method varies slightly, depending on whether you are digging bare soil or a plot covered with turf.
Before burying or stacking turves, consider whether some of them could be used to renovate a worn area of lawn.
Digging the soil two spits deep allows roots to penetrate more deeply, releases fresh reserves of nutriments and improves drainage.
Even so, not many gardeners find time for double digging. If you decide to try it, experiment on part of the plot to judge whether the effect is worthwhile.
Final preparation of soil for sowing and planting will be straightforward if digging and manuring were completed by Christmas, or soon after. In the meantime it will have been crumbled by the action of frost, rain and drying winds.
Fortunately, suitable soil conditions generally coincide with the higher temperatures and longer days needed forof spring crops. However, the weather is not always in step with the calendar, so be guided by conditions in your garden, rather than the ideal sowing dates suggested elsewhere in this website or by seed merchants.
On clay soils, especially, you must wait until the soil is dry enough to be walked on without it sticking to your boots or shoes, or becoming compacted.
Immediately before sowing or planting, rake the top few inches to break the remaining lumps into a crumb-like structure.
For small seeds, such as lettuce and carrots, this needs to be as fine as possible. Larger seeds, such as broad beans and peas, will grow in slightly rougher conditions.
If the surface has been compacted by heavy rain it will need loosening with the tips of the fork tines before it can be raked. Do not disturb more than the top inch or two, and walk backwards to avoid treading on the loosened surface. Allow it to dry before giving the final raking.
If you were unable to dig during the winter, make as early a start as possible in the spring so that the soil has time to settle before crops are sown or planted.
A fork is better than a spade for this late digging as it will turn and break the soil in a single operation.
Although most spring cultivations are concentrated on the top inch or two of soil, deeper forking is a help before planting potatoes. This crop does best in a loose, open soil, even if it is somewhat rough and lumpy.
For this reason, fork over the potato plot well in advance of planting, breaking up the soil thoroughly to a depth of one spit.
Cultivating between crops
Land cleared of one crop in the middle of the season, and then planted with another, must be cultivated in between. A garden fork is the best tool and the depth of cultivation will depend on the condition of the soil.
After lifting early potatoes, for instance, the soil will need little more than levelling and raking. Where spring cabbages or some other long-standing crop has been grown it will be necessary to loosen and break up several inches of the top spit. In both cases allow as long as possible for the soil to settle before sowing or planting another crop, and then firm it additionally with your feet.